The present invention relates to wind assisted cooling for wind turbine generators and particularly relates to a cooling system which utilizes flow induced pressure and suction to receive cooling air from the ambient environment and routes the cooling air to the wind generator parts susceptible to thermal related degradation.
Wind turbine generators typically stand on pylons hundreds of feet in the air. The generators include a hub mounting two or typically three airfoil blades which drive the generator. Within the nacelle mounting the hub, a rotor is rotated by the airfoil blades and hub. Rotation of the rotor either through a direct drive system or a gearbox causes relative rotation between magnetic poles and coils to generate electricity. In the direct drive generator, the rotor rotates at the same speed as the blades rotate and consequently a large radius is required to obtain the tangential velocity required to produce electricity. A gearbox of course, increases the rotational speed to a high value, e.g., 1000 RPM which itself causes problems.
As with any generator, heat is generated and it is necessary to cool the various parts of the generator. The cooling of a wind generator must be done efficiently to minimize losses and it will be appreciated that space restrictions prevent the use of elaborate cooling pipes, blowers, filters, heat exchangers and the like to facilitate cooling. Traditional generator cooling apparatus has been bulky, expensive and difficult to maintain. Because of the nature of wind turbine generators and the need to locate the generators hundreds of feet above ground while at the same time providing cooling for the generator, there is an established need to provide an improved cooling system for wind turbine generators e.g., to utilize wind flow around the nacelle to assist airflow ingestion into and exhaustion of heated air from the nacelle for purposes of cooling the generator.